This invention relates to containers and is more particularly concerned with improvements in product containers which are in the form of a tray and which are adapted to be fabricated from paperboard which is coated with a film forming material of a character which will withstand oven temperatures commonly employed in bakeries and enable the container to be used for processing and marketing of products which may be in a flowable state when initially placed in the tray, such as, bakery products.
Tray containers have been developed heretofore which are particularly adapted for use in the bakery industry where the product may be processed in an oven and subsequently marketed without removing it from the container in which it has been processed. Products such as cakes, pastry, and the like are generally in a flowable state initially, that is, in a liquid or semi-liquid condition, and it is a requirement that the container be leakproof when filled to a predetermined level with the product and capable of withstanding oven temperatures during the baking process without damage from the heat so that the baked product may be marketed without removal from the container. For such products, containers have been developed which are adapted to be formed from thin metal foil or relatively stiff metallic sheet material which can be pressed or shaped to the desired form and become part of the final package in which the product is marketed. Such containers are generally expensive and lacking in aesthetic appeal since they do not readily accept the inks commonly employed in decorative printing. Efforts have been made, with some success, to provide non-metallic trays which are suitable for this purpose. One such tray structure is disclosed in U.S. Pat. No. 4,114,797 granted Sept. 19, 1978. A further tray development is disclosed in application Ser. No. 036,326, filed May 7, 1979. However, it appears that there is a need for trays of this type which have greater rigidity or stiffness, particularly in the sidewall panels and which are otherwise more convenient for use in the handling of certain materials in the bakery industry.
It is a general object therefore of the present invention to provide an improved open top tray structure of the type described which has greater rigidity than trays of this type heretofore produced, which is more economical to manufacture than similar trays formed of metal foil, and the like, and which affords greater convenience in use, particularly, in the preparation and marketing of bakery products.
It is a more specific object of the invention to provide an improved tray structure and a method of forming the same in which the tray is fabricated from a paperboard blank which is coated with a film of plastic material having sufficient heat resisting characteristics to withstand oven temperatures commonly employed in the baking industry, which may be safely used in microwave ovens, and which may be supplied to the user as a cut and scored blank, or partially folded blank, so that it can be set up with side and end wall panels upstanding from a rectangular bottom wall panel and connected at the corners by pairs of integral web members which are folded upon each other and against the outside face of an end wall with tab members for reinforcing the corner connections which tab members extend inwardly of the opposite ends of the end walls and are sealed to end wall reinforcing and covering panel members at each end, which panel members are integral with the top edge of the end wall and are folded down so as to overlie the end wall and the associated folded corner web members and which have marginal portions folded underneath and adhesively secured to the bottom wall panel.
It is a further object of the invention to provide a tray structure of the type described and a method of fabricating the same so as to provide integral reinforcing and covering panel members on the sidewall and end wall panels which covering members are disposed in overlying double wall panel relation on the outside of the side and end wall panels, with the end wall reinforcing and covering members being adhesively connected to tab members forming end extensions on the sidewall members which are folded to lie against the end wall panels of the tray and with the end margins of end wall reinforcing and covering members folded into engagement with and adhesively secured to bottom wall panel portions.
The invention as herein disclosed and claimed comprises a tray structure and a method of forming the same from a cut and scored blank of paperboard coated with a heat resistant plastic film material which tray structure comprises a bottom wall forming panel and oppositely disposed pairs of peripherial sidewall forming panels which are integrally hinged into upstanding relation with the bottom wall forming panel and connected at the intersecting corners by pairs of integrally hinged triangular web members folded into overlying relation on the outside face of the one sidewall panel and secured by corner reinforcing tab members which are disposed beneath a reinforcing and covering panel member which is intergrally hinged to the top edge of the associated sidewall forming panel and turned down into overlying relation with the sidewall forming panel and with portions of the bottom wall panel to which end portions thereof are adhesively secured.